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June 2014
Atlanta Georgia
Timothy Wadhams
Michael S. Holden
Matthew MacLean
Comparisons of Experimental and Computational Results from “Blind” Turbulent Shock Wave
Interaction Study Over Cone Flare and Hollow Cylinder Flare Configurations
Sponsored by CUBRC Internal Research, NSSEFF grant with
University of Minnesota, and AFOSR
Outline of Presentation
• Comparison between Earlier Measurements for High Reynolds
Number Hypersonic Regions of Shock Wave/Turbulent Interaction
Over HIFiRE 1 and Flat Plate/Wedge/Shock Generator Configurations
(Open Test Cases)
• Program Objectives and Review of Model Geometries: Large Cone
Flare and Hollow Cylinder Flare
• Presentation of Comparison Results from Large Cone Flare
• Review of Case with Submission of Different Codes, Grid Resolution
and Models
• Presentation of Comparison Results from Large Hollow Cylinder
Flare
• Summary and Discussion Results
Program Objectives and Experimental Program Design
• Obtain Detailed Heat Transfer and Pressure Measurements in
Regions of Shock Wave/ Fully Turbulent Boundary Layer
Interactions to Evaluate Models of Turbulence Employed in Codes.
• Conduct Program at Duplicated Mach 5, 6, 7 and 8 Flight Velocities
and in Cold Flows on Models the Size of Typical Flight Vehicles.
• Employ Axisymmetric Models and Flow Conditions to Obtain
Well-Defined Interaction Regions and Well Defined Boundary
Conditions Upstream and Downstream of the Interactions [laminar
heat flux and cone/cylinder pressure upstream and attached, post
peak pressure downstream].
• Distribute Model Geometries and Measured Freestream
Conditions in Invite Letter in March 2014 to 15 Perspective
Participants, 4 of which presented today and will be compared to
experimental results.
• Locations of Boundary Layer Transition on Cone and Cylinder
given in San Diego 2014 AIAA Paper by Holden
Earlier Results from Open Code Validation Cases – Available from AIAA and CUBRC
7° HIFiRE Cone Large 7° Cone/
Flare
Flat Plate / Wedge
Configuration
Flat Plate / Shock Generator
Configuration
AIAA Paper Listings Available in 2013 San Diego Paper and from CUBRC Directly
Heat Transfer Measurements in Transitional and Turbulent Flows Over HIFiRE 7° Cone at Duplicated Mach 6.5 and 7.2 Flight Conditions
Run 4 (M=6.5) Run 6 (M=7.2)
Run Mach U
(m/s)
(kg/m3)
T
(K)
Nose radius
(mm)
4 6.5 1925 0.125 213 2.5
5 7.2 2185 0.070 232 2.5
6 7.2 2185 0.071 231 5.0
8 6.5 1930 0.126 214 5.0
Flux Limiter Modifications to Turbulent Models Required to Match Experimental Data [33 deg. HIFiRE-1 Flare]
65.065.0
2211
68
~
tanh1,
~01.1
,75.0max,25.1min
Sd
CCb
LIM
b
Modified SA Model with
Turbulence Flux Limiter
Matching specific
experimental
measurements requires
empirical “fix” to current
turbulence models.
Measurements on Full-Scale HIFiRE-1 at Mach 7.2 Duplicated Flight Conditions
6
Flare Heating Prediction with Wilcox Modified Reynolds Stress Limiter, CLIM=0.90
Adjusting stress limiter coefficient on SST model provides good qualitative
agreement with separation length and distributions in separated regions
Turbulent Shock Wave/Boundary Layer Interaction: Wedge-Induced Separation
Run M Re/ft T, K Wedge
angle
12 8 40E6 70 27°
16 8 40E6 70 30°
19 8 40E6 70 33°
24 8 40E6 70 36°
54 11 10E6 60 36°
DPLR with flux limiter (CLIM=0.90) significantly overpredicts length of separated region
and peak heating in reattachment region
Turbulent Shock Wave/Boundary Layer Interaction: Shock-Induced Separation
Run M Re/ft T, K SG angle
49 11 10E6 60 20°
DPLR with flux limiter (CLIM=0.90) significantly overpredicts length of separated region but is in
good agreement with heat transfer downstream of the attachment
AFOSR 7° Cone M=10 Flight Enthalpy Measurements
- Cone half angle: 7°
- Angle of attack: 0°
Run Mach
U
(m/s)
(kg/m3)
T
(K)
Nose
radius
(mm)
19 10 2845 .012 205 2.5
20 10 2850 .012 205 Sharp
8-ft, 7° cone installed in LENS I facility
Run 20
Large Double Cone and Hollow Cylinder/Flare Models Employed in Experimental Studies to Produce Measurements for “Blind” Validation Test Cases
Flight Matching and Cold Flow Freestream Conditions Employed in SWTBLI Studies on Large Cone Flare Configuration
Details of Cases Submitted
• Received detailed submissions from groups at NASA Langley
Research Center, NASA Ames Research Center, University of
Minnesota, and Texas A&M University, also plot solutions from
CUBRC
• All submission work was performed with researchers code of
choice, and all submissions at a minimum included a case
performed with the SST turbulence model, primary comparison
• Some submissions also provided with other models, will compare
• Comparisons will be presented in interaction region pressure,
interaction region heat flux, and forebody heat transfer
Interaction
Region Forebody
Heat
Transfer
Cone/Flare Mach 5 Cold Flow, ReL 120x106 – Run 26
• Mach 5, Cold Flow Case, Highest Reynolds
Number
• All submissions over predict the separated
region, evident in pressure plot
• Peak pressure and heat transfer magnitudes
predicted well and downstream pressure levels
compare well
• Predicted peak location is downstream of
experimental peak, in line with larger predicted
separation length
• No fully laminar data for this case to compare
Cone/Flare Mach 5 Flight Velocity Flow, ReL 35x106 – Run 28
• Mach 5, Flight Velocity Case
• All SST submissions over predict the separated region,
evident in pressure plot, S-A model achieves correct
separation length
• Peak pressure magnitudes predicted well and
downstream pressure levels compare well
• Predicted peak location is downstream of experimental
peak, in line with larger predicted separation length
• SST model submissions over predict peak heat flux, S-A
model predicts downstream heat flux, under predicts the
peak heat flux
• Laminar heat flux data well predicted, similar variation in
turbulent hear flux as previous case
Cone/Flare Mach 6 Cold Flow, ReL 45x106– Run 33
• Mach 6, Cold Flow Case
• All SST submissions over predict the separated region,
evident in pressure plot, S-A model achieves closer
separation length
• Peak pressure magnitudes predicted well, some over
prediction, downstream pressure levels compare well
• Predicted peak location is downstream of experimental
peak, in line with larger predicted separation length
• SST model submissions over predict peak heat flux, S-A
model predicts downstream heat flux, under predicts the
peak heat flux
• Laminar heat flux data well predicted, tighter closer
prediction of turbulent hear flux
Cone/Flare Mach 6 Flight Velocity Flow, ReL 37x106 – Run 45
• Mach 6, Flight Velocity Case
• Experimental data shows no or incipient separation (see
Schlieren frame)
•All SST submissions over predict the separated region,
evident in pressure plot, S-A model predicts attached flow
• Downstream pressure levels compare well
• Predicted peak heat flux location is downstream of
experimental peak, in line with larger predicted separation
length
• SST model submissions over predict peak heat flux, S-A
model under predicts downstream heat flux
• Laminar heat flux data well predicted, forebody turbulent
flux well predicted, one case higher
Cone/Flare Mach 7 Flight Velocity Flow, ReL 12x106 – Run 43
• Mach 7, Flight Velocity Case
• Experimental data shows no likely incipient separation
(see Schlieren frame)
•All SST submissions over predict the separated region,
evident in pressure plot, S-A model predicts attached flow
• Downstream pressure levels compare well
• Predicted peak heat flux location is downstream of
experimental peak, larger predicted separation length
• SST model submissions over predict peak heat flux
lesser extent than Mach 6, S-A model under predicts
downstream heat flux
• Laminar heat flux data well predicted, forebody turbulent
flux well predicted, one case lower
Cone/Flare Mach 8 Cold Flow, ReL 34x106
– Run 37
• Mach 8, Cold Flow Case
• All SST submissions over predict the separated region,
evident in pressure plot, S-A model achieves slightly
under predicted separation length
• Peak pressure magnitudes predicted well, some over
prediction, downstream pressure levels compare well
• Predicted peak location is downstream of experimental
peak, in line with larger predicted separation length
• SST model submissions over predict peak heat flux,
close downstream, S-A model under predicts flare heat
flux
• Laminar heat flux data well predicted, tighter close
prediction of forebody turbulent hear flux
Cone/Flare Mach 8 Flight Velocity Flow, ReL 11x106– Run 41
• Mach 8, Flight Velocity Case
• Experimental data shows no to incipient separation (see
Schlieren frame)
•All SST submissions over predict the separated region,
evident in pressure plot, S-A model predicts attached flow
• Downstream pressure levels compare well
• Predicted peak heat flux location is downstream of
experimental peak, larger predicted separation length
• SST model submissions over predict peak heat flux, S-A
model under predicts flare heat flux
• Laminar heat flux data well predicted, forebody turbulent
flux well predicted, one case lower
Comparison of Code, Grid Resolution, and Turbulence Model
• Peter Gnoffo submitted several variations on code, grid, and
model
• Mach 5, Cold Flow, Highest Reynolds Number, No Observed Fully
Laminar Flow on Cone
• LAURA solution with S-A model achieves closest match to
separated region length, FUN3D with K-Omega largest over
prediction
• Downstream pressures well predicted, FUN3D with K-Omega as
well if plot carried out further, peak pressure magnitude well
predicted, peak predicted downstream
• SST model achieves proper heat flux peak magnitude, S-A cases
under predict peak, K-Omega under predicts flare heat flux
Hollow Cylinder/Flare Mach 5 Flight Velocity Flow, ReL 32x106– Run 17
• Mach 5, Flight Velocity, Low Reynolds Number
• All submissions over predict the separated region,
evident in pressure plot
• Peak pressure under predicted, peak heat flux
over predicted with exception of S-A, downstream
pressure levels compare well, NASA and CUBRC
DPLR solutions agree well
• Predicted peak location is downstream of
experimental peak, in line with larger predicted
separation length
• Fully laminar data agrees well, variation on
turbulent heat flux
Hollow Cylinder/Flare Mach 5 Flight Velocity Flow, ReL 63x106– Run 16
• Mach 5, Flight Velocity, High Reynolds Number
• All submissions over predict the separated region,
evident in pressure plot
• Peak pressure under predicted, peak heat flux
over predicted with exception of S-A, downstream
pressure levels compare well, NASA and CUBRC
DPLR solutions agree well
• Predicted peak location is downstream of
experimental peak, in line with larger predicted
separation length
• Fully laminar data agrees well, variation on
turbulent heat flux
Hollow Cylinder/Flare Mach 6 Flight Velocity Flow, ReL 17x106– Run 11
• Mach 6, Flight Velocity, Low Reynolds Number
• All submissions over predict the separated region,
evident in pressure plot
• Peak pressure predicted well, peak heat flux over
predicted with exception of S-A, downstream
pressure levels compare well, NASA and CUBRC
DPLR solutions agree well
• Predicted peak location is downstream of
experimental peak, in line with larger predicted
separation length
• Fully laminar data agrees well, variation on
turbulent heat flux, mostly over predicted
Hollow Cylinder/Flare Mach 6 Flight Velocity Flow, ReL 53x106– Run 13
• Mach 6, Flight Velocity, High Reynolds Number
• All submissions over predict the separated region,
evident in pressure plot, all very similar
• Peak pressure predicted well, peak heat flux over
predicted (No S-A), downstream pressure levels
compare well
• Predicted peak location is downstream of
experimental peak, in line with larger predicted
separation length
• Fully laminar data agrees well, variation on
turbulent heat flux, mostly over predicted
Hollow Cylinder/Flare Mach 7 Flight Velocity Flow, ReL 17x106 – Run 18
• Mach 7, Flight Velocity
• All submissions over predict the separated region,
evident in pressure plot, all very similar
• Peak pressure predicted well, peak heat flux over
predicted with the exception of S-A, downstream
pressure levels compare well
• Predicted peak location looks to be better
predicted in this case
• Fully laminar data agrees well, variation on
turbulent forebody heat flux, range of agreement
Hollow Cylinder/Flare Mach 8 Flight Velocity Flow, ReL 11x106 – Run 21
• Mach 8, Flight Velocity
• All submissions over predict the separated region,
evident in pressure plot
• Peak pressure predicted well, peak heat flux over
predicted, with the exception of S-A which under
predicts peak but gets downstream heat flux,
downstream pressure levels compare well
• Predicted peak location is downstream of
experimental peak, in line with larger predicted
separation length
• Fully laminar data agrees well, variation on
turbulent heat flux, one case under predicts
Summary of Results
Summary:
• Dataset of turbulent shock interaction results now available for comparison to
research and design tools and associated turbulence models
• All submissions presented here compare well with upstream and downstream
pressure, and with available laminar heat flux upstream of transition, nice check
on provided freestream conditions, prediction of attached laminar flow solved
at this point
• Forebody turbulent heat flux prediction varied case to case, some predicted
well
• Most submissions employing SST model over predicted interaction region
length, S-A model closer to correct length when separated, predicted attached
flow
• Most submissions (SST) show over prediction of heat flux downstream of
interaction, higher Mach number cone flare cases exception, S-A tends to
under predict peak heat flux downstream of interaction
Questions for Discussion
• We observe better prediction of forebody heat-flux in these cases
than was shown in earlier cases (HIFiRE-1 and Mach 10 Enthalpy
Cone), how much does this influence interaction region agreement?
• Observe, particularly in hollow cylinder flare case, that specifying
transition location does not change result, how does transition
location influence comparison?
• Cone Flare comparisons show variation in interaction length between
submissions, Hollow Cylinder flare shows little to no variation in
length, Mach 8 case shows the most, should DPLR solutions match?
• Thoughts on S-A producing better agreement of separation length and
under prediction of heat flux on flare
• Hot wall experiment
• Near wall fluctuation measurements with Focused Laser Differential
Interferometry (FLDI)
• Data release time frame and process
Next Steps
• Data Release:
• Data will be transmitted to presenters within the next two weeks
• Will include specified freestream conditions, model geometries, surface
pressure and heat flux, standard deviation values for mean interval, and
uncertainty information
• Other individuals and groups may also obtain the results by contacting Mike
Holden and Tim Wadhams at CUBRC, will be emailed as requests come in
• Data considered to be Distribution A, Public Release
• Currently planning a second round of work and presentations at
a future AIAA session, will inform the original set of invitees, any
others let us know
• Further Experiments
• Wall temperature variation to explore Tw/To ratio independent of enthalpy
• Near wall turbulence fluctuation measurements, considering techniques,
currently pursuing Focused Differential Laser Interferometry (FLDI) [small
measurement region] and in stream stagnation temperature fluctuation